A total of 161 calls were challenged in Miami, of which 53 were successful.

"We could not be more pleased with how the video review system worked in its first use, but I also feel this first tournament showed a lot about the professionalism and skill of our line judges," said Gayle Bradshaw, the ATP Administrator of Rules & Competition.

"We look forward to evaluating the entire process, and we will work in the coming months to improve the challenge system in order to make the experience even better for players, spectators and the television viewers."

The WTA's Angie Cunningham said: "Our players have really been impressed with the system, and they are finding out just how hard it can be to call a ball travelling at the speeds that our players hit it these days."